Consider gandering through the pages of MacWorld in 2004-2005 for some ideas and context, you can get it at
https://www.vintageapple.org/
Magazine reviews and overviews were lots (maybe not all, but definitely "lots") of how people found out about software back in the day. MacWorld had a reasonably strong Internet presence by then so you may be able to find stuff on their site, lots of stuff from the era (like the MMMM editorial
) still exists on their site today.
Above and beyond that, is there something you're looking to do or some experience you wish to get?
This is the absolute bulk of what existed for Macs in this era.
Add iWork, iLife, and AppleWorks 6 (will work on Intel up to 10.6 via Rosetta) to that, just to see Apple's evolving ideas on personal productivity and pack-in tools (although iwork was on sale separately in a box until a bit after 2010 or so.)
Beyond that most of what I used at the time was applications tied to services that don't exist, such as AOL Radio and communications tools tied to services that mostly don't exist any more, like iChat/AIM/MSNM/Adium, an IRC client (XChat-Aqua for me) and although I wasn't into text editors at the time, BBEdit is a great one and I think I would've liked then.
I also add SuperDuper to my personal toolbag and it's what's on my snowtemplate image. It's also worth fetching a quicktime pro key, just for convenience.
Roughly speaking, the year 2010 or 2011 is when things started shifting from on-prem perpetually licensed software (important point: software licenses were never actually "perpetual", there was just no technological means by which Microsoft could withdraw your ability to use Excel 97) toward subscriptions and even web-based cloud services. There were a few earlier forays into this, I was using Google Docs offline mode in Firefox on the train back in 2008, but it was by far and away the exception, not the rule in those times.
In a lot of ways, a hallmark of modern computers is that there's not really "matched versions" any more, just... the most current version that exists. In fifteen or thirty years it's a real toss-up as to whether anyone's going to care that Zoom even had version numbers, for example, given that the client's functionality is really pegged to the service's status at any given moment, both in terms of logging in and in terms of time-travel not really being possible. This goes further with web oriented services because it's not like there's a version of "YNAB" or gmail.com that looks best on, say, mac os x 10.13, because the web ultimately embraces being a window inside the main box, even if that window's importance and size has grown over the years.